Jane Goodall

And they appear to be searching for sight or sound of neighbors.

And that the males of a community, any number from four to ten, depending on the size of the community at the time, will actually...

enlarge their territory at the expense of a weaker neighbor.

So it's not only protecting their territory for their females and young, but an act of warfare almost, to increase their own territory.

We had one period at Gombe, which was I think the darkest period in Gombe's history,

which we refer to as the Four Year War.

And it happened after the main study group had divided.

And there was a period when there was a sort of no man's land between the two communities, newly established rangers.

And then the males of the larger community, the Kasakela community, began going on raids into the heart of the land that had been taken over by the splinter group that moved off to the south.

And if they encountered an individual on his or her own, they would give chase.

It was almost like a hunt.

And once they captured such an individual, they would subject him or her to a really, really brutal and sustained attack.

Nothing like that happens within a community.

This is very...

special to inter-community interactions.

And the chimps, particularly the young males, appear to enjoy this kind of conflict.

And the young male will actually go back into a danger zone and peer at the enemies.

They also show patterns when they attack strangers that they never showed during intra-community fighting, that's fighting within their community, such as bending, twisting a limb round and round, drinking blood, tearing the skin, the sort of thing you see when they're trying to kill an adult prey animal.

Yes, it suggests if we believe in Darwinian evolution, if we believe as Lewis did, and I do, that at one time we shared a common ancestor, then it seems fairly clear that we have inherited certain violent tendencies from our ancient primate ancestors.

ancestors.